Semi-automatic tamping machine



Oct. 21, 1958 J. T. GORSUCH 2,856,667

SEMI-AUTOMATIC TAMPING MACHINE Filed June 18, 1954 fiyrezylbr (fa/717 TGama/7 y W1? m5 United rates Patent O flflce 2,856,667 Patented Oct. 21,1958 2,856,667 SEMI-AUTOMATIC TAMPIN G MACHINE Application June 18,1954, Serial No. 437,776 2 Claims. (CI. 25-27) This invention relates toa semi-automatic tamping machine, and more particularly, to asemiautomatic machine or apparatus for uniformly and repetitivelytamping or spreading clay in a mold and for applying a uniform oil filmto the spread clay.

In the prior ceramic or porcelain electrical insulator manufacturingart, a ball of clay formed by hand was positioned in a mold. Then, anoperator spread or tamped the ball of clay in the mold by manuallypressing downwardly on the ball of clay with a felt and canvas coveredmallet, plunger, or tamper. If the ball of clay is properly spread ortamped in the mold, the clay has a shape acceptable for plunging. Priorto the plunging operation, the operator applied a film of oil by hand tothe spread or tamped clay. Plunging is the final forming operationwherein a heated die is used to press intricate shapes into the tampedclay. Oil is applied to the tamped clay preparatory to the plungingoperation to facilitate a uniform release of the heated plunging diefrom the clay.

The above-described manual operations of tamping the clay and applying afilm of oil to the tamped clay are slow, costly, and result in a highrate of rejection. Tamping is a very critical operation requiringconsiderable operator skill, and is subject to the errors of operatorjudgment. For instance, the operator may tamp the ball of the clay toodeeply, not deep enough, or too much on one side. Also, due to acombination of errors in operator judgement and the rather crude tamperemployed, sometimes the tamper was not uniformly released from thespread clay resulting in flaws such as suck and folds. Furthermore,applying oil to the tamped clay by hand preparatory to plunging didnotalways result in the application of a uniform oil fihn to the tampedclay.

It is an object of this invention to remove the abovedescribed defectsby providing a machine for uniformly tamping clay in a mold foruniformly applying an oil film to the tamped clay and for affecting auniform release of the tamper from the tamped clay.

In a clay tamping tool comprising a tamper having an outer covering suchas felt and canvas, my invention comprises a high pressure gas pocket orcushion formed between said tamper and covering.

In an instrument for spreading clay in a mold comprising a reciprocatingplunger having an outer cloth covering such as canvas and an absorbentpad such as felttherebetween, my invention further comprises a uniformflow of a lubricating and cooling fluid such as oil to said pad throughchannels or grooves formed in said plunger.

My invention further comprises a machine or apparatus having an uprightclosed piston cylinder positioned directly above a mold holder and atamper disposed between said cylinder and holder and connected by apiston rod to a reciprocating piston within said cylinder, a source ofhigh pressure fluid alternately connected to opposite ends of saidcylinder by a four-way spool valve and two fluid conduits connected tosaid valve and said opposite ends, and a two-way spring biased spoolvalve communicating With said source and connected by a fluid conduit tosaid four-Way valve for initiating downward movement of said tamper, anda vertically adjustable two-way spring biased cam operated spool valvecommunicating with said source and connected by a fluid conduit to saidfour-way spool valve for initiating upward movement of said tamper aftera predetermined downward movement thereof, and a cam movablesimultaneously with said tamper engageable with said cam operated valveafter said predetermined downward movement.

My invention eliminates the heretofore raising and lowering of thetamper or mallet by hand, spreads the ball of clay in the mold to thesame shape in each and every case, eliminates the sticking of clay tothe plunger or mallet, eliminates those defects due to hand tamping, andapplies a uniform coating or film of oil to the tamped clay.

The features of my invention which I believe to be novel are set forthwith particularity in the appended claims. My invention itself, however,both as to its organization and method of operation, together withfurther objects and advantages thereof, may best be understood byreference to the following description taken in connection with theaccompanying drawing.

In the drawing, Fig. 1 is a perspective view of a preferred form of myinvention. Fig. 2 is a diagrammatic view of my preferred form ofinvention. Fig. 3 is a View of a tamped ball of clay. Fig. 4 is asectional view of the tamper of my invention, the section being takenalong the line 4-4 of Fig. 1. Like reference numerals will be usedthroughout the various figures to indicate identical parts.

Referring now particularly to Fig. 1, shown therein is a machine frame 1having a mold holder 2 adapted to hold and center a mold 3. Within themold 3 is positioned a ball of clay 4. An upright high pressure fluidpiston cylinder Shaving its axis common with the axis of mold 3 issupported by frame 1 directly above mold holder 2 in vertically spacedrelationship therewith... A tamper, plunger, or mallet 6 is adapted tobe reciprocated by the piston cylinder 5. As will be more clearhereinafter, depression of a foot lever 7 initiates downward travel ofthe tamping tool 6 to spread or tamp the ball of clay 4 into the shapeillustrated in Fig. 3. After a predetermined downward stroke of the clayspreading instrument 6, a cam or arm 8 will engage a verticallyadjustable two-way spring biased cam operated spool valve 9. Actuationof valve turn movement of the tamper 6.

Referring now also to Fig. 2, a not shown source of high fluid pressuresuch as a tank of high air pressure is connected by a high fluidpressure conduit 10 to a fluidly operated four-way spool valve 11. Valve11 comprises a closed cylindrical housing 12 having a slidable triplepiston valve element therein. Formed in the side wall of housing 12 anddistributed along the length thereof are five apertures or ports.Conduit 10 is connected to the central one of said five ports. A highfluid pressure conduit 13 is connected to the port immediately to theleft of said central port and to the upper end of cylinder 5. Anotherhigh fluid pressure conduit 14 is connected to the port immediately tothe right of said central port and to the lower end of cylinder 5. Eachof conduits 13 and 14 has a throttle valve (VT) for a purpose well knownin the art. The two endmost ports 15 and 16 of said five ports areexhaust ports in communication with the ambient air or the like.

A two-way spring biased spool valve 17 is connected to conduit 10 by apipe or tube 18 and to the left-hand end of four-way valve 11 by a pipeor conduit 19. Twoway valve 17 which is adapted to be actuated by footlever 7 comprises a cylindrical housing having a slidable.

spring biased double piston valve element therein.

9 by cam 8 initiates upward re- Formed in the housing side wall oftwo-way valve 17 are three ports or apertures distributed along thelength thereof. The central one of said three ports is connected to tube19, and tube 18 is connected to the upper one of said three ports. Thelower one of said three ports is an exhaust port and is in communicationwith the atmosphere or the like.

Two-way vertically adjustable spring biased cam operated spool valve 9comprises a cylindrical housing having a slidable spring biased doublepiston valve element therein. Formed in the housing side wall of valve 9and distributed along the length thereof are three ports or apertures.The central one of said three ports is connected by a flexible hose 20to the right-hand end of four-way valve 11, and the left-hand port ofsaid three ports is connected by a flexible hose 21 to the conduit ortube 10. The right-hand port of said three ports is an exhaust port incommunication with the atmosphere or the like.

The tamper 6 is connected by a piston rod 22 to a piston 23 disposedwithin the cylinder 5. The cam or arm 8 movable simultaneously with thetamper 6, piston rod 22, and piston 23 is adapted to engage a finger orcam arm 24 of valve 9 after a predetermined downward stroke of tamper 6to drive the slidable spring biased double piston valve element of valve9 leftwardly.

When the foot lever 7 is depressed, the downwardly spring biased doublepiston valve element of valve 17 is moved upwardly whereby tube 18 is incommunication with tube 19 while the exhaust port of valve 17 isisolated therefrom. Accordingly, high pressure fluid from conduit 10will go through tubes 18 and 19 into the left-hand end of valve 11 todrive the slidable triple piston valve element thereof towards theright. The triple piston valve element of valve 11 will remain at theright-hand end of housing 12 inasmuch as the righthand end of housing 12is exhausted through the flexible hose 20 and exhaust port of valve 9while the tube 21 is isolated therefrom. When the triple piston valveelement of valve 11 is driven towards the right, the tubes 10 and 13 arein communication with each other and are isolated from the exhaust ports15 and 16 and the tube 14. Accordingly, high pressure fluid will enterthe upper end of cylinder 5 through the tubes 10 and 13 to drive thetamper 6 downwardly. When the tamper 6 is initiated downwardly inasmuchas the triple piston valve element of valve 11 is in its right-handposition, the lower end of cylinder 5 is exhausted through tube 14 andexhaust port 16.

After a predetermined downward stroke of the tamper 6 to press the ballof clay 4 into the shape illustrated in Fig. 3, the cam 8 will contactthe cam arm 24 to drive the cam operated spring biased double pistonvalve element of valve 9 to the left. When the double piston valveelement of cam operated valve 9 is driven to the left, hoses and 21 arein communication with each other and are isolated from the exhaust portof valve 9. With tubes 20 and 21 communicating with each other, highpressure fluid is conducted from conduit 10 through pipes 21 and 20 intothe right-hand end of valve 11 thereby driving the triple piston valveelement of valve 11 leftwardly. An operator cannot prohibit leftwardtravel of the triple piston valve element of valve 11 by keeping thefoot lever 7 depressed. After the foot lever 7 is depressed to initiatedownward travel of the tamper 6, the left-hand end of foot lever 7 willtravel beyond the lower protruding end of the piston rod of the doublepiston valve element of valve 17. Therefore, even though an operatorretains his foot on foot lever 7 after the tamper 6 has been initiateddownwardly the spring of valve 17 will be free to drive the doublepiston valve element of valve 17 downwardly to place the tube 19 incommunication with the exhaust port of valve 17 while the tube 18 isisolated therefrom. Accordingly, when the cam or arm 8 actuates the camoperated valve 9 to initiate return travel of the tamper 6 the left-handend of four-way valve 11 will have been exhausted via the pipe 19 andthe exhaust port of valve 17. After the triple piston valve element offour-way valve 11 is driven leftwardly, the conduits 10 and 14 are incommunication with each other and simultaneously isolated from theexhaust ports 15 and 16 and the conduit 13. Therefore, high pressurefluid will enter the lower end of the cylinder 5 through conduits 10 and14 to raise the piston 23. With the triple piston valve element of valve11 positioned at the left-hand end of the housing 12, the tube 13 isplaced in communication with the exhaust port 15 while tube 13 andexhaust port 15 are each isolated from the conduits 10 and 14 andexhaust port 16. Therefore, when high pressure fluid passes into thelower end of the cylinder 5 to withdraw the tamper 6, the upper end ofcylinder 5 is automatically exhausted through the tube 13 and exhaustport 15.

As better seen in Fig. 1, the valve 9 is carried in a verticallydisposed slot or guideway 36. By loosening the set screws 37, the valve9 can be moved vertically upwardly or downwardly. Since the valve 9 isvertically adjustable the stroke of the tamper 6 can be readilyadjusted.

After the tamper 6 has returned to its uppermost position, the mold 3and its tamped ball of clay can be removed from the mold holder 2 andthe mold holder 2 can be reloaded with another mold and ball of clay foranother identical tamping operation. The left-hand end of foot lever 7comprises two levers capable of buckling with respect to each other.When the operator removes his foot from foot lever 7 the spring 25 offoot lever 7 will cause the left-hand end of foot lever 7 to buckle andpass beneath the valve 17 whereupon another reciprocating cycle of thetamper 6 can be initiated. After the two levers of the left-hand end offoot lever 7 have buckled with respect to each other and passed beneaththe valve 17 a spring 26 will straighten said buckled levers.

Referring now to Fig. 4, it will be seen that the clay spreading tool orinstrument 6 preferably comprises a solid steel bowl-shaped mallet,plunger, or tamper head member 27 having a rounded or curved convexunderside. The tamper head member 27 has an outer porous flexible clothcovering 28, such as canvas or the like. Disposed between the roundedunderside of tamper head member 27 and outer cloth covering 28 is anabsorbent pad 29, such as felt or the like. Pad 29 is slightly spacedfrom the curved underside of tamper head member 27 by a shallow gaspocket or cushion 30. Stem or piston rod 22 is connected to the tamperhead member 27 at the side thereof opposite to the rounded underside.Formed in the top side of tamper head member 27 is an inlet port havinga T-fitting outlet ports 32 are formed in said curved or roundedunderside of the tamper head member 27 and outlet ports 32 are incommunication with the inlet port having T-fitting 31 connected theretoby grooves formed within the solid member 27. Connected to the T-fitting31 are two flexible hoses 33 and 34. The hose 33 is in communicationwith a high pressure gas or air source, as by connection of hose 33 toconduit 10. Hose 33 has a valve (V) disposed therein for adjusting theflow of air through hose 33 and outlet ports 32 into the gas pocket orcushion 30. The inflated gas pocket or cushion 3t flexes upon tampingand facilitates a uniform release or departure of the tamper 6 from thespread or tamped clay and eliminates sticking of the spread of tampedclay to the tamper 6.

Hose 24 is connected to a source of cooling and lubricating fluid, suchas a tank or container of oil 35. Tank 35 preferably is positioned about2 feet above the head member of tamper 6 when tamper 6 is in its raisedposition. When the tamper 6 travels downwardly, the increase inhydraulic head differential will cause a uniform flow or dripping of oilthrough the hose 34 and outlet ports 32 31 connected thereto. Aplurality of' to the absorbent cloth or felt pad 29 and the outerflexible porous cloth or canvas covering 28. Pad 29 acts as a blottersoaking up this flow of oil similar to an ink stamping pad. Accordingly,the tamper 6 automatically and repetitively applies a uniform film orcoating of oil to each body of spread or tamped clay. A valve (V) isinserted in flexible hose 34 for adjusting the flow of oil to pad 20.

While there has been shown and described a particular embodiment of theinvention, it will be obvious to those skilled in the art that changesand modifications may be made without departing from the invention, andthat it is intended by the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a reciprocating clay tamping tool, a solid steel bowl-shapedtamper head having a rounded convex surface adapted to tamp clay, saidtam-per head having an outer canvas cover and a felt pad disposedbetween said cover and rounded surface, said pad spaced from saidrounded surface to define a shallow air cushion therebetween, aplurality of outlet apertures formed in said rounded surface, an inletaperture formed in another surface of said tamper head opposite to saidrounded surface, channels formed in said solid tamper head connectingall of said outlet apertures to said inlet aperture, two flexible hosesconnected to said inlet aperture, one of said hoses continuouslycommunicating with a source of compressed air to inflate said aircushion, the other of said hoses continuously communicating with asource of oil to saturate said pad and cover with oil.

2. A machine for uniformly tamping clay in a mold with a felt and canvascovered mallet and for effecting a uniform departure of said mallet fromclay tamped by said mallet and for uniformly lubricating clay tamped bysaid mallet comprising a mold holder, an upright closed cylinderpositioned directly above said mold holder, a piston in said cylinder,said mallet disposed between said cylinder and mold holder and connectedto said piston by a piston rod, a source of high pressure fluidalternately connected by a four-way fluid valve and two fluid conduitsto opposite ends of said cylinder, said source of high pressure fluidconnected by a fluid conduit and a two-Way cam operated fluid valve tosaid four-way fluid valve, a cam carried by said mallet engageable withsaid two-way cam operated fluid valve, said mallet having at least oneoil groove formed in a felt and canvas covered surface portion thereof,and said source of high fluid pressure and a source of oil incommunication with said oil groove.

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